JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
        
        <div id="arrow4" class="arrow">
            <div class="red">START HERE!</div>
        </div>
    
<div id="main">
        
         <div class="way">1</div>
        <div class="way">2</div>
        <div class="way">3</div>
        <div class="way">4</div>
        <div class="way">5</div>
        <div class="way">6</div>
        <div class="way">7</div>
        <div class="way">8</div>
        <div class="way">9</div>
        <div class="way">10</div>
        <div class="wall">11</div>
        <div class="wall">12</div>
        <div class="wall">13</div>
        <div class="wall">14</div>
        <div class="wall">15</div>
        <div class="wall">16</div>
        <div class="wall">17</div>
        <div class="wall">19</div>
        <div class="wall">20</div>
        <div class="way">21</div>
        <div class="way">22</div>
        <div class="way">23</div>
        <div class="way">24</div>
        <div class="way">25</div>
        <div class="way">26</div>
        <div class="way">27</div>
        <div class="way">28</div>
        <div class="way">29</div>
        <div class="wall">30</div>
        <div class="way">31</div>
        <div class="way">32</div>
        <div class="wall">33</div>
        <div class="wall">34</div>
        <div class="wall">35</div>
        <div class="wall">36</div>
        <div class="wall">37</div>
        <div class="wall">38</div>
        <div class="way">39</div>
        <div class="wall">40</div>
        <div class="way">41</div>
        <div class="way">42</div>
        <div class="wall">43</div>
        <div class="way">44</div>
        <div class="way">45</div>
        <div class="way">46</div>
        <div class="way">47</div>
        <div class="wall">48</div>
        <div class="way">49</div>
         <div class="wall">50</div>
          <div class="way">51</div>
          <div class="way">52</div>
          <div class="wall">53</div>
          <div class="way">54</div>
         ...

CSS

#main {
    width: 350px;
    height: 350px;
    float: left;
    margin-left: 220px;
    margin-top: 100px;
    background: grey;
    overflow: hidden;
}
body { 
background: #6cc5c3;
 font-family: 'HelveticaNeue-UltraLight', 'Helvetica Neue UltraLight', 'Helvetica Neue', Helvetica, Arial,  sans-serif; font-weight: 100; letter-spacing: 1px;
}

.way {
    width: 35px;
    height: 35px;
   background: #2e8dad;
    float: left;
}

.wall {

    width: 35px;
    height: 35px;
   background: #fff;
    float: left;
    
}

#wrapper {
    
    width: 550px;
    margin: 0 auto;
    
}
.arrow {
    margin-top: 130px;
    position: absolute;
    color: #fff;
    font-weight: bold;
    margin-bottom: 5px;
}

#arrow4:after {
    content: '';
    height: 0;
    display: block;
    border-color: transparent transparent transparent #fff;
    border-width: 20px;
    border-style: solid;
    position: absolute;
    top: 0;
    left: 160px;
}

.red {
    height: 20px;
    padding: 10px;
    width: 140px;
    color: #6cc5c3;
    background: #fff;
    text-align: center;
}

#lose {
    width: 550px;
    display: none;
    background: #e8e5e0;
}

#highlight_win {
   display: none;
    margin: 0 auto;
}

div.smileyface {
	width: 300px;
	height: 300px;
	position: relative;
	border-radius: 150px;
	-webkit-border-radius: 150px;
	-moz-border-radius: 150px;
	display: block;
	background: #ffe632;
	background: -webkit-gradient(linear, left top, left bottom, from(#fffe8d), to(#f6d23e));
	background: -moz-linear-gradient(top,  #fffe8d,  #f6d23e);	
	box-shadow: inset 0px -14px 14px rgba(0, 0, 0, .3), 0px 2px 20px rgba(0, 0, 0, .6);
	-webkit-box-shadow: inset 0px -14px 14px rgba(0, 0, 0, .3), 0px 2px 20px rgba(0, 0, 0, .6);
	-moz-box-shadow: inset 0px -14px 14px rgba(0, 0, 0, .3), 0px 2px 20px rgba(0, 0, 0, .6);
	}
	
p.eyes {
	width: 50px;
	height: 80px;
	background: #222;
	border-radius: 100px/160px;
	-webkit-border-radius: 100px 160px;
	-moz-border-radius: 100px/160px;
	position:...

JavaScript

$('.wall')
.bind('mouseenter', function() {
    $(this).css({
        'background-color': 'green'
    });
})